In this second R01 application revision (DA15075), a randomized clinical trial is proposed to evaluate the efficacy of a drug abuse prevention intervention for indicated middle school youth that coordinates family and teen-based components. The Family Management Intervention is comprised of a parent-focused curriculum to foster parenting skills followed by brief family therapy to foster adaptive family communication and age-appropriate roles. The Teen Achievement Intervention is comprised of a clinician-delivered learning strategy curriculum to foster academic achievement followed by a similar yet peer-facilitated curriculum to foster self-efficacy and prosocial peer networks. In the first study aim, we seek to evaluate the separate and possibly synergistic effects of the Family Management and Teen Achievement components on post intervention drug use, problem behavior, psychological distress, and academic achievement of indicated youth. Innovative analytic strategies are subsequently used to elucidate mediated pathways by which the interventions might reduce drug involvement and problem behavior by promoting changes in targeted skills and behavior change processes. The possibility of effect-modification also is considered, with a focus on neurocognitive, internalizing/externalizing, and demographic factors, in an effort to discern why interventions work for some youth but not others. This application revision has sought to address well-taken concerns cited by the reviewers while maintaining proposal strengths. In response to a key limitation, this revision includes further specification of anticipated relationships between neurocognitive variables, skill acquisition levels, and prevention intervention outcomes among indicated youth. Study hypotheses on specific neurocognitive effects are informed by empirical findings and the clinical experience of investigative team members specializing in neuropsychology. If successful, this project should improve prevention practices by identifying malleable behavior change processes fostered by effective interventions. Improving our understanding of how individual characteristics of indicated youth, such as neurocognitive deficits or externalizing problems, influence the development of skills during interventions and subsequent outcomes may also help to improve existing prevention interventions. The significance of the proposed study is underscored further by the substantial size of the targeted population of indicated youth, and the range of morbidities and mortality that often result when early warning signs of drug abuse are not addressed.